Bacillus thuringiensis isolates active against cockroaches

Abstract

The subject invention concerns novel materials and methods for the control of cockroaches. Cockroaches are common house pests, and they create problems in hospitals, the food industry and in agriculture. According to the subject invention, activated toxins of Bacillus thuringiensis var. israelensis (B.t.i.) are used to control cockroaches. In one embodiment, the subject invention also concerns the use of B.t. PS123D1 to control cockroaches. A truncated form of a toxin obtained from PS123D1 having particular activity to cockroaches is also claimed for use in controlling the pest.

We claim: 
     
       1. A method for controlling cockroaches which comprises feeding said cockroaches an effective mount of a Bacillus thuringiemsis var. israelensis toxin of between about 25 kD and about 33 kD as measured by SDS PAGE. 
     
     
       2. The method, according to claim 1, wherein said toxin is truncated compared to the full length toxin as it is naturally expressed. 
     
     
       3. The method, according to claim 1, wherein said toxin is from Bacillus thuringiensis isolate PS123D1, having the activity against cockroaches characteristic of NRRL B-21011; or a mutant of said isolate which has activity against cockroaches. 
     
     
       4. The method, according to claim 1, wherein said cockroaches are selected from the group consisting of German cockroaches (Blatella germanica), Oriental cockroaches (Blatta orientalis), American cockroaches (Pedplaneta americana) and Brown cockroaches (Pedplaneta americana). 
     
     
       5. The method, according to claim 1, wherein said cockroaches are German cockroaches (Blatella germanica). 
     
     
       6. The method, according to claim 1, which comprises growing in culture said Bacillus thuringiensis var. israelensis under conditions which facilitate the activation of said toxin by raising the pH of the culture. 
     
     
       7. The method, according to claim 6, wherein said activation is effected by the truncation of said Bacillus thuringiensis var. israelensis toxin. 
     
     
       8. The method, according to claim 1, which comprises adding a protease to a Bacillus thuringiensis var. israelensis culture, or a supernatant thereof. 
     
     
       9. A method for controlling cockroaches which comprises (1) preparing a bait comprising a Bacillus thuringiensis var. israelensis isolate; or spores, crystals, or toxins of said isolate; and   (2) placing said bait in areas visited by cockroaches.